$1,585 Cheap United flights Barcelona (BCN) to San Diego (SAN)

Scoring cheap one-way United Airlines flights from BCN to SAN from $1,585 on Expedia is a breeze — just filter by "Price (lowest to highest)." Alternatively, check out our affordable return fares from $798 for your next exciting getaway.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Start your search for United Airlines flights from BCN to SAN about one month before you want to go. The most affordable time to book an international flight is generally 18 to 29 days ahead of your travel date when you can save 17% versus booking four to five months in advance. Regardless of ticket type or itinerary, the best day of the week to book international airfare is usually Sunday. Friday is often the most expensive. Travelers who book on a Sunday can save an average of 17% compared to those who book on a Friday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

Search United Airlines's earliest flights from BCN to SAN by using our "Morning" and "Early Morning" filters. Not only will you arrive sooner, early departures also have a 20% less chance of being canceled.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.

A rewarding loyalty program and the chance to rack up points through United Mileage Plus are the start of the reasons to travel from BCN to SAN with United Airlines. Plus, when you sign up to Expedia's free One Key™ program, you can earn OneKeyCash™* on top of any airline loyalty program earnings. It's yours to spend on future travel plans.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.